Mobile device, such as smart phone, has become indispensable to modern people in their everyday life. The smart phone has the function of taking photos and some smart phones further provide the function of modifying the photos with different configuration and settings. For example, if the photo is a photo of portrait, the photo will be modified by beatifying the skin color. If the photo has the image of sky, the color of the sky will be modified to be bluer.
However, the ways of modifying the photos with predetermined configuration and settings in the smart phone may not meet the requirement of all users. If the user wants to modify the photo in some particular way, he has to use the computer to modify the photo. For example, the user may adjust the color of the photo, the contract of the photo, or the brightness of the photo by himself with the assistance of software, such as Photoshop. It is very time consuming, and actually most of the users have no idea about how to modify the photo. Besides, a computer is often needed to modify the photo in this way. Therefore, how to provide an easy and convenient way to modify the photo to meet the preference of the user becomes a prominent task for the industries.